Overview
- The Phase 1 study enrolled 14 women treated in Germany and Sweden after surgery and chemotherapy for triple-negative breast cancer.
- Ten of the 14 participants remain disease-free at a median follow-up of 62 months, three died after cancer progression, and one died of unrelated causes.
- Investigators observed activation of both CD4+ and CD8+ T cells against vaccine-selected neoantigens in all participants, with response magnitude and duration varying by patient.
- Each patient received an individualized mRNA vaccine encoding up to 20 tumor-specific neoantigens, administered as eight intravenous doses over nine weeks.
- BioNTech’s chief medical officer says the results demonstrate feasibility, safety, and durable immunogenicity rather than proven efficacy, with Phase 2 trials ongoing in other cancers through a Genentech partnership and no decision yet on a Phase 2 for this indication.